Blackboard-eraser



(NoMdel) T, H. COSTELLO.

BLAGKBOARD BRASER.

No. 412,876. Patented Oct. 15, 1889.

N. PETERS. whuwumo nu. Warhiuglnm 11c UNITED STATES AIENT OFFICE,

THOMAS H. OOSTELLO, OF LAKE, ASSIGNOR TO A. H. ANDREWS dz COMPANY,

OF CHICAGO, ILLINOIS.

BLACKBOARD-ERASER.

SPECIFICATION forming part of Letters Patent No. 412,876, dated October 15, 1889.

Application filed June 20, 1889i Serial No. 315,015. (No model.)

To all whom it may concern.-

Be it known that I, THOMAS II. COSTELLO, residing in the town of Lake, in the county of Cook and State of Illinois, and a citizen of 5 the United States, have invented a new and useful Improvement in Blackboard-Erasers, of which the following is a specification, reference being had to the accompanying drawings, in which- Figure 1 is a side elevation.

under side view.

This invention relates to blackboard-eras ers of the class shown in Letters Patent of the United States No. 190,662, dated May 15,

I5 1877, granted to Herbert L. Andrews.

As heretofore made, blackboard-erasers of this class have been rectangular in form and the corners have been either rounded or square, which renders it difficult to erase small lines and marks or a single character without erasing adjacent lines or characters.

The object of this invention is to provide an improved blackboard-eraser which will avoid the above objection and at the same time improve the construction of the erasingsurface, which I accomplish as illustrated in the drawings, and as hereinafter described and claimed.

In the drawings, A represents a block of Wood which forms the handle of an eraser.

One or both ends of this block A are cut diagonally to the sides, thereby forming an acute angle a with one of the sides.

I) c are strips of felt or other suitable ma- 3 5 terial for an erasing-surface, which are glued or otherwise secured to the block A. The

Fig. 2 is an side strips 1) are secured, one along each side edge of the block A, and a number of crossstrips 0 are secured diagonally across the'space between the side strips and parallel to the ends 1. of the block A. The end strips 0 and side strips 1) also form an acute angle at the acute angle a of the block A, thus furnishing a point which may be used for erasing small lines and marks or a single character Without erasing or rubbing the adjacent characters or marks. The spaces between the strips 0 form channels in which the chalk may collect. The diagonal strips 0 also form abettererasingsurface than that furnished by strips placed at right angles to the sides of the block or by those placed parallel to the sides of the block, as has been proven by actual test.

What I claim as new, and desire to secure by Letters Patent, is 1. As an improved article of manufacture,

a blackboard-eraser comprising a block-handle having one end extending at an acute angle to its side, and felt or other erasive material secured to the face of the blockhandle, and having one end extending at an acute angle to the side and coinciding with the acute-angled end of the block-handle, substantially as described.

2. A blackboard-eraser comprising a blockhandle having its opposite ends extending diagonally to its sides to form acute angles a, the parallel side erasing-strips 17, secured to the block-handle and having diagonal ends to form acute angles coinciding with the acute angles at the ends of the block-handle, and diagonal erasing-strips a, secured to the block-handle between the parallel side strips, substantially as described.

THOS. H. COSTELLO. lVitnesses:

HARRY T. J ONES, ALBERT H. ADAMS. 

